Electrical controllers



March 6, 1956 E. Q. MEAD 2,737,548

ELECTRICAL CONTROLLERS Filed May 11, 1953 3 Sheets-Sheet l March 6, 1956 Q MEAD 2,737,548

ELECTRICAL CONTROLLERS Filed May 11, 1953 5 Sheets-Sheet 2 March 6, E. Q M D ELECTRICAL CONTROLLERS 3 SheetsSheet 3 Filed May 11, 1955 FOR United States Patent ELECTRICAL CONTROLLERS Edward Q. Mead, Milwaukee, Wis., assignor to Cutler- Hammer, Inc., Milwaukee, Wis., a corporation of Delaware Application May 11, 1953, Serial No. 354,001

Claims. (Cl. 200-18) This invention relates to electrical controllers and while not limited thereto is particularly adapted for controlling the driving motor speed of a printing press.

More specifically, this invention is particularly adapted for use with the Multi-Position Electrical Controller of Jochem Patent No. 2,672,579, granted March 6, 1954, and assigned to the assignee of the present application. The present invention will be explained in terms of its cooperation with the controller of said Patent No. 2,672,579, and the several parts shown in the drawings herein which are structurally and functionally identical with those shown and described in said Patent No. 2,672,579 are identified by the same reference characters as the corresponding parts in said Patent No. 2,672,579.

It is often desirable to provide a printing press motor control with a predetermined speed setting so that when the press is stopped and subsequently restarted, it will automatically come up to the predetermined speed setting. It is further desirable to be able to change this speed setting from a remote control station during operation of the press so that a new operating speed can be attained and so that subsequent stopping and restarting will automatically bring the motor up to the new speed setting. It is a primary object of this invention to provide a motor driven controller which is adapted to permit change of the preset speed from a remote control station.

Another object is to provide a controller of the aforementioned type which will respond to operation of the usual run button to return the motor to the last operating speed established during the next preceding running operation.

Another object is to provide a controller of the aforementioned type which, during running operation of the motor, is operable to effect a change in operating speed in accordance with the duration of time which a remote push button station is held depressed.

A more specific object is to provide a controller of the aforementioned type having a faster and a slower remotely located push button control station, so that during running operation of the motor, closure of either of said push buttons will effect the corresponding change in operating speed and to the degree determined by the time duration of such closure.

The novel features which I consider characteristic of my invention are set forth with particularity in the appended claims. The device itself, however, both as to its organization and mode of operation, together with additional objects and advantages thereof, will best be understood from the following description of a specific embodiment when read in connection with the accompanying drawings, in which- Figure 1 is a fragmentary elevational view of a set of cam-operated switches operatively associated with the preset speed mechanism;

Fig. 2 is a sectional view taken, in the direction of the arrows, along the broken line 2-2 of Fig. 1;

Fig. 3 is a sectional view taken, in the direction of the arrows, along the broken line 3-3 of Fig. 1;

Fig. 4 is a sectional view taken, in the direction of the arrows, along line 4-4 of Fig. 3; and

Fig. 5 diagrammatically illustrates an electrical control system for the controller driving motor.

Referring to Fig. 1, it shows only a portion of the interlock switch drum 71 shown in Figs. 10, 14, 15, 17, and 18 and explained in the specification of said Patent No. 2,672,579. Although a brief description of several of the parts of said interlock switch drum 71 will be hereinafter included in order to show the inter-relation and cooperation of the present invention therewith; whereas it is intended that reference will be made to said Patent No. 2,672,579, for a complete understanding of the operation of said drum 71.

Operating shaft 72 is supported in brackets 300 (only one of which is shown) on ball bearings (not shown). Annular members 159 are welded to said brackets to atford added bearing surface for the last mentioned ball bearings. Shaft 72 and these ball bearings are restrained against movement upwardly or downwardly relative to brackets 300 by plates 160 secured to the outer surfaces of said brackets 300 as shown in Fig. 1.

Drum 71 comprises a plurality of plunger operated switch units 161, similar in construction and arrangement to those disclosed in Patent No. 2,521,519, granted September 5, 1950, to Richard B. Hunter and Harold L. Mekelburg. Switch units 161 are enclosed and supported in alined groups of three in pairs of interfitting, molded insulating blocks 162 and 163, which are similar in general arrangement and construction to corresponding switch supporting blocks shown in the aforementioned Hunter et al. patent. Each of the switch units 161 is biased to circuit closed position and has a plunger actuator 161 with a roller follower 161 attached to the end thereof. A plurality of the interfitting switch blocks 162 and 163 are supported in a row on a pair of supporting shafts 164, which are rigidly secured at their ends to brackets 300.

Each of the roller followers 161 of the switch units 161 has associated therewith an operating cam 165. The cams 165 are carried on a shaft 166 which is non-rotatabiy secured to the brackets 300. Each of the cams 165 is secured, as by welding, to a hub portion 167 of a gear 167 which extends through a clearance opening in the cam. The assembly comprising a cam 165 and a gear 167 is rotatably mounted on a flanged bushing 163 which in turn is rotatably mounted on shaft 166. The end of each of the bushings 168 seats against one end of a gear 167 and serves to space adjacent cam and gear assemblies from each other on shaft 166.

The gears 167 are a special form of twelve teeth gear having four teeth 167 extending across the full width of the gear and spaced at rotary angles of 90 about the periphery of the gear, and have eight teeth 167 extending from one face of the gear only part way across the width thereof. A pair of the teeth 167 are interposed between any two of the full-length teeth 167 The teeth 167 and 167 have the same profile and are equally spaced about the periphery of gear 166. Four arcuate concaved depressions 167 are formed in the hub portion 167* adjacent the ends of the pairs of teeth 167 (See Figs. 17 and 18 of said Iochem Patent No. 2,672,579.)

An assembly comprising a laminated two-toothed gear sector 169 and a notched circular disc 170 cooperate to afford intermittent drive and locking of each of the gears 167. Gear sector 169 comprises teeth 169- and 169 which are formed integrally with an attaching portion 169 (Fig. 2). Sector 169 is rigidly secured to the disc 170 so that the notch between the teeth of the former alines with a correspondingly formed notch 170 in the latter. Disc 170 is provided with a central clearance opening 170 for shaft 72 and is also provided with an elongated arcuate opening 170. Disc 170 is adjustably, non-rotatably secured to a disc 171 by means of a bolt 172 penetrating opening 170 and threading into one of twelve threaded openings 171 formed in disc 171. Disc 171 is preferably smaller in diameter than disc 170 and is provided with a square central opening to receive the corresponding square portion 72 of operating shaft 72, there by insuring non-rotatable securement of said disc on said shaft 72. The assemblies comprising gear sector 16%, disc 171) and disc 171 are spaced from the other such assemblies on the portion 72 of shaft 72 by annular spacing collars 173 (Figs. 1 and 4) positioned on said shaft.

Operating shaft 72 extends upwardly beyond the bracket 3% (not shown) and is attached, by a suitable gear train or other type of power transmission, to a pilot motor PM (see Fig. 5). It is to be understood that operation of the pilot motor PM causes rotation of said shaft '72.

The cam surfaces of the cams 165 are provided with a high portion 165 a low portion 1165 and an intermediate portion 165 for effecting transition between said high and low portions.

The operation of the above-explained gears, cams and switches is described in detail in the aforementioned Jochem Patent No. 2,672,579. In order to point out the coordination and inter-relation of such parts with the instant invention, it is only necessary to note that as said shaft 72 rotates, the gear teeth of gear sector 159 engage the gear teeth on gear 167 thus causing cam 165 to rotate relative to roller follower 161 When said cam 165 rotates sufficiently, switch 161 is operated to open position by movement of plunger actuator 161 relative to cam surfaces 165 and 165% It is thus seen that the operation of the several switches 161 can be coordinated to effect the necessary sequential control operations while the secondary resistance of the drive motor (such as printing press drive motors) is varied in small increments.

In order to run the drive motor at a predetermined speed setting, it is only necessary to stop the pilot motor PM at such desired speed during the resistance stepping operation. The pilot motor can be stopped in accordance with a predetermined speed setting by utilizing one of said switches 161 as a limit switch so that rotation of shaft 72 will effect opening of said limit switch, which is shown diagrammatically and designated by the reference character LS161 in Fig. 5, thereby disconnecting the pilot motor PM from its source of power at the predetermined setting. Operation of pilot motor PM simultaneously effects rotation of shaft 72 and operation of a main switch drum (not shown); the latter of which effects the actual secondary resistance stepping. in order to change the speed setting at which said limit switch LS161 operates, a novel, adjustable preset speed control, to be hereinafter described, is provided. As seen in Fig. 1, the lowermost switch 161 is the above-mentioned limit switch LS161 and is similar in every detail to said switches 161. For actuation of said limit switch 1.5161, a cam member 301 is secured, as by welding, to a hub portion 167 of a gear 167 which extends through a clearance opening in the cam member. The gear 167, to which is attached said cam member 301, is mounted on shaft 166 as hereinbefore explained with regard to the other gears 167 and cams 165.

For engagement with the teeth on said gear 167 is a gear sector 169 having gear teeth 169 and 169 (Figs. 2 and 3) for engagement with gear teeth 167* on said gear 167. Such gear sector 169 is attachedto a disc 392., as shown in Fig. 3. Disc 302 is provided with an opening 3%.2 of sufficient size to permit shaft 72 to rotate relative to said disc 302 as hereinbefore explained with regard to the mounting of discs 170. Non-rotatably attached to said disc 332 is a gear member 303 provided with a centrally located opening 3173 (Fig. 4) to permit relative rotational movement between shaft 72 and gear memher 333.

Said disc 302 and said gear member 303 are attached to each other by means of bolts 304 and nuts 305, as best illustrated in Fig. 4. Interposed on the shanks of said bolts 304, between said nuts 305 and said disc 302, are compression springs 306 which urge said disc 302 toward said gear member 303.

Interposed between said disc 302 and said gear member 303 is a friction disc 307 associated with the square portion 72 of shaft 72 in a manner to prevent relative rotational movement therebetween. At the lower end of said gear member 303 (see Fig. 4) there is adjusting means for the components mounted on said shaft 72, in-

' eluding a nut 177 threadedly engaging the threaded portion 72 of operating shaft 72.

The periphery of said gear member 303 is provided with gear teeth 393 for engagement with gear teeth 308 on hub 303 of a ratchet gear 308 (Figs. 1 and 3). Ratchet gear 308 is rotatably mounted on a shaft 309 and is positioned thereon by means of spacers 310 (Fig. l). Shaft 309 is mounted between bracket 300 and one side of a U-shaped bracket 311 as shown in Fig. 1.

Also positioned between said bracket 300'and one side of said .U-shaped bracket 311 is a shaft 312, affording pivotal mounting of an arm 313 (Fig. 3). One end of said arm 313 is centrally positioned on said shaft 312 by means of spacers 314 (Fig. 1).

Attached to the other end of said arm 313 as by means of a nut and bolt assembly 315 is an armature 316*- of an electromagnet 316. Said arm 313 is U-shaped as best shown in Fig. 1, and thus provides a pair of side members 313 and 313 Positioned between said side members 313 and 313 and intermediate the ends thereof is a pin 318 (Fig. 3) for engagement with and disengagement from the toothed periphery of ratchet gear 308 as said arm 313 is selectively pivoted about said shaft 312.

Electromagnet 316 has a winding 316 mounted on flange portions 311 and 311 of U-shaped bracket 311. Also attached to arm 313 is one end of a tension spring 313. The other end of spring 319 is attached to electromagnet winding mounting bracket 320, which is secured to flange portions 311 and 311 of the U-shaped bracket 311 as shown in Figs. 1 and 3. It is thus seen, as shown in Fig. 3, that spring 319 urges arm 313 in a direction to effect disengagement of pin 318 from ratchet gear 308. Further it will be seen that as the electromagnet winding 316 is energized, armature 316 will overcome the bias-,

ing effect of spring 319 to cause pin 318 to engage the toothed periphery of ratchet gear 308.v

The mechanical operation of the presetting device will now be explained.

As the running operation is begun, the main drive motor and the pilot motor PM are energized simultaneously. Energization of the pilot motor causes the main switch drum (not shown) to operate to successively change the secondary resistance of the main driving motor,

thereby increasing the speed of said main drive motor by small increments. During such stepping operation, rotation of shaft 72 (also operated-by pilot motor PM) causes rotation of disc 302 and gear member 303 by means of the biasing effect of compression springs 306 causing said disc 302 and gear member 303 to frictionally engage said friction disc 307. Rotation of disc 302 eventually effects engagement between gear sector 169 and gear 167, thus causing cam member 301 to rotate. Sufficient rotation of cam member 301 causes limit switch LS 161 to disconnect pilot motor PM, from its source of power supply, thereby stopping operation of the main switch drum and rotation of shaft 72. The main drive motor is thus caused to operate at a constant speed. During this entire operation, pin 318 is disengaged from ratchet gear 308 due to the biasing effect of tension spring 319.

It is further seen that with pin 318 in engagement with the saw tooth periphery of ratchet gear 308, cam member 301 would not be able to rotate even though pilot motor PM would be energized to effect rotational movement of shaft 72. During such operation, friction disc 307 would rotate between and relative to disc 302 and gear member 303. Gear member 303 and disc 302 would be restrained against rotation due to the engagement between the gear teeth on ratchet hub portion 308 and the gear teeth on the periphery of said gear member 303. It is thus seen that with pin 318 in engagement with ratchet gear 308, cam member 301 is not permitted to rotate to effect operation of limit switch LS161, notwithstanding the rotational movement of shaft 72. It is further seen that such non-rotation of said cam member 301 will permit the stepping operation to continue unabated, thereby causing the main drive motor to reach a different preset speed setting.

A preferred electrical control circuit for effecting operation of the preset speed mechanism in cooperation with the pilot motor PM and a main drive motor is shown in Fig. 5, and will now be explained. Contact sets 401, 401 and 401 of electromagnetic switch 401 operate under the influence of winding 401 to commutate the power supply to the main drive motor (not shown). It will be appreciated that said contact sets would be connected in the electrical circuits between the said drive motor and its source of power; whereas in Fig. 5 such connections are not shown, it being understood that such an arrangement is well known in the art.

The pilot motor PM is connectible to the source of power, lines L1, L2 and L3, through forward contact sets 402, 402 and 402 d for forward operation thereof, and through reverse contact sets 403, 403 and 403 for reverse operation thereof. As above-explained, pilot motor PM is connected to shaft 72 for effecting coordinated operation of the several switches 161.

To operate the main drive motor, it is only necessary to momentarily close the run switch 404. Closure of switch 404 energizes winding 401 of electromagnetic switch 401 thus closing contact sets 401, 401 and 401 and connecting the drive motor to its source of supply. With the drive motor connected to the source of power, it is only necessary to energize the pilot motor PM in the forward direction to effect the successive resistance steps in the secondary circuit of said drive motor to bring the same up to operating speed.

Energization of pilot motor PM is effected by closure of contact set 401. Such closure effects energization of winding 405 through a circuit composed of contact sets 406 and 401 and limit switches LS161 and 408. Energization of winding 405 effects energization of winding 402 through a circuit consisting of contact sets 405 and 409. Energization of winding 402 closes contact sets 402, 402 and 402 thus establishing power connections to the pilot motor PM and operating the same in the forward direction. Due to the holding circuit completed by contact set 401, switch 404 may be released without affecting the operation of the drive motor or the operation of the pilot motor PM. Thus, the pilot motor operates to change the secondary resistance and the speed of the drive motor until the limit switch LS161 opens the circuit to winding 405 causing deenergization of winding 402 and disconnection of the pilot motor PM from the source of power. Such disconnection of pilot motor PM must be synchronized with the most favorable operating condition or position of the switches which make up the main switch drum and determine the drive motor operating speed, to thus avoid excessive contact arcing and to insure optimum closure of the contacts of such switches.

Such synchronizing is more fully explained in the abovementioned Iochern Patent No. 2,672,579, but will be very'briefly herein explained to bring out the desirable cooperative action with the present invention. Suflice it to say here that the optimum time for disconnection of pilot motor PM is when cam 4,10 operates to close contact set 410. It is thus seen that it is necessary to disconnect pilot motor PM when cam 410 closes contact set 410 for the first time following opening of limit switch LS161.

The aforementioned energization of winding 402 effects closure of contact sets 402 and 402% the latter of which contact sets, sets up an energizing circuit for winding 410 so that subsequent closure of contact set 410, by action of cam 410 completes such circuit comprising contact set 402, 409 and 405. Closure of said contact set 402 also effects energization of winding 411 of electromagnetic switch 411 through a circuit including contact set 410. Contact set 411 is closed due to energization of said winding 411, thus setting up a holding circuit for winding 402 by virtue of the circuit composed of contact sets 411, 402 and 409. Thus even though the winding 405 is eventually deenergized by reason of opening of limit switch LS161, the forward contact sets 402, 402 and 402 will not be opened due to opening of contact set 405, but will remain closed by virtue of the holding circuit composed of contact sets 411, and 402. To provide continuous energization of winding 411 during speed increasing operations, a holding circuit composed of contact set 405 is provided for contact set 410. Thus opening of contact set 410 will have no effect on winding 411 unless the speed increasing operation has been terminated by virtue of opening of said contact set 405 As soon as cam 410 effects closure of contact set 410, energization of winding 410 opens contact set 410, thereby deenergizing winding 411 and opening contact set 411. Such opening of contact set 411 effects deenergization of winding 402 since the usual energizing circuit therefore has been previously opened by virtue of opening of contact set 405. This, of course, opens forward contact sets 402, 402 and 402 at the optimum moment, namely, when cam 410 closes contact set 410, so that the pilot motor PM and shaft 72 are brought to rest with the stepping switches in their proper positions.

If it is desired to increase this preset speed setting during operation of the main drive motor, it is only neces sary to depress the faster switch 412 until the desired operation speed is obtained. Closure of switch 412 closes contact sets 412, shorting out limit switch LS161 and energizing winding 405, which effects energization of winding 402 by virtue of closure of contact set 405. Thus pilot motor PM is operated in the forward direction due to closure of contact sets 402, 402 and 402 thereby increasing the speed of the main drive motor (not shown).

Simultaneous with the energization of winding 405 is energization of winding 413 of electromagnetic switch 413. Switch 413 is provided with time delay means, represented by a dashpot in Fig. 5, by which contact set 413 is afforded instantaneous closure and timed opening. Instantaneous closure of contact set 413 effects energization of winding 316 of electromagnetic relay 316, thus causing pin 318 to engage ratchet gear 308 of Fig. 3, as above-explained. In this manner the limit switch LS161 is held fixed while pilot motor PM rotates to effect a new preset speed setting.

During such operation, windings 410 and 411 are prepared as above-explained for approaching running speed operation, and function in the same manner when the faster" switch 412 is released as above-explained due to release of run switch 404. The only additional operation following release of switch 412 and preceding closure of contact set 410, as above-explained, is the continued closure of contact set 413 due to its timed opening feature thus insuring engagement of pin 313 with ratchet gear 308 until after the pilot motor PM is completely disconnected from lines L1, L2 and L3.

Such newly selected preset speed is then fixed so that subsequent stopping and restarting of the main drive motor inthe .usuahmanner, will'bring said .drive motor up to the newly selected speed.

:In .order to decrease the preset speedsetting during operation of the drive motor, it is only necessary to .depress the slower switch 495 until the desired speed setting is reached. Closure of switch 406 closes contact set 4% thus energizing winding 41B through acircuit composed of said contact set 406 and the thenclosed limit switch 414. Switch 414- is a mechanically operated slowlimit switch which opens during stopping operation or slowing operation when the drive motor is near zero .speed, to thus disconnect the reverse :power connections to the pilot motor PM. Upon restarting of .the main drive motor, said limit switch 414 is reclosed as said drive motor begins to gain speed.

.Energization of winding 4tl9 'closes contact set409 energizing winding 4% vof electromagnetic switch 403 through a circuit composed of contact sets 409' and'4tl5 and limit switch 414. Thus reversepower isappliedlto pilot motor PM through contact sets 403 4ii3 and-403 causing pilot motor PM toxrotate shaft 72 in a reverse direction, and to operate the mainswitchdrum (not shown) in a direction to *effect successive resistance changes in the secondary circuit of the main drive motor to decrease the drive motor speed.

Depression of switch 406 opens contact set 406 thus maintaining winding 405 deenergized to insure against completion of the forward power connections to motor PM while the reverse power connections, initiated by energization of winding 4il are completed.

Switch 486 is also provided with contact set 406, closure of which completes the energizing circuit for winding 413 to thereby energize winding 316 as aboveexplained. This, of course, locks cam member 301 to hold. limit switch LS161 in its open position, so that subsequent release of switch 406 will effect complete disconnection of power supply to pilot motor PM.

Energization of windings 409 and 403* close contact sets 409 and 403, respectively, thus providingcontinw ous energization of winding 411 through said contact sets to establish a holding circuit consisting of contact sets 411t and H33 so that subsequent deenergization of winding 44W and opening of contact set 409 will not deenergize winding 403 to disconnect the reverse power connections to pilot motor PM; whereas such power connections will be maintained until cam 410 closes contact set 410 at the optimum position .of the resistance stepping switches, as above-explained.

Contact sets 34E (forward operation) and 409' (reverse operation) are opened due to energization of their respective windings 495 and 4tt9 to insure against .energization of winding Mil until the respective forward or reverse" stepping operations have been completed. Thus winding @11 cannot be deenergized until said windings 495 and 499 are both deenergized and cam 410 has closed contact set 418.

Contact sets 4il5 (forward operation) and 409 (reverse operation) are opened due todeenergization of their respective windings to insure against simultaneouscomplction of the forward and reverse power connections for said pilot motor PM. Such contact sets are normally closed and are opened to insure disconnection of the opposite direction pilot motor. connections.

Immediately following either forward or reverse operation of pilot motor PM, contact set 413 will remain closed due to its timed opening feature to insure complete power disconnection from the pilot motor before pin 318 is disengaged from ratchet gear 3%. This of course maintains optimum closure conditions of limit switch 1.8161.

Limit switch 4%8 is mechanically operated by shaft 72 to disconnect the forward power connection to ,pilot motor Plvlwvhcn the highest speed stepping switch is reached. This insures "against mechanical and electrical complications due to operation of the pilot motor beyond .8 saidrlastispeed setting. Said limit switch 408, of course, closes res-soon as the main switch drum begins its .re- -verse;steppin g rotation from the highest speed setting.

In ordcrttorstop the main drive motor, it is only necessary totmomentarily depress stop switch 417. Depression of :switch 417deenergizes winding 401*, thus removing powereconnections to the drive motor by virtue ofsopening.ofcontactsets-401 401 and 401 Deenergizationtof winding'401 'efiects closure of contactset 401 therebyiinitiat'mg reverse operation of pilot motor PM :as za'boveaexplained. .-During such reverse operation of pilottmotoraPM'to efiect stopping of the drive motor, cam member -.301 is permitted to rotate with shaft72, thereby maintaining the angular relation between said-cam.member 301 and cam members so that subsequentrestarting :of the drive motor, due to closure-of run .switch 404, will cause the drive motor to attainanoperatingspeedequal to the preset speed effectedtduring the .running operation next preceding the stoppingpperat-ion of-.the drive motor.

;.It will benotedthat-thestopping operation will continuein thesame manneras.above explained for decreasing the ,.preset speed setting, until limit switch 414 is mechanically openednearzerospeed of the drive motor, thusgpermittingthesamertocoast to a complete stop. 7

Opening of limitswitch 4.14, of course, completely de-energizes the entire .controlsystem, pilot motor PM and.the main drive motor. Subsequent restarting is effected:by reclosure of the run switch 404 as aboveexplained.

:It is:thus:seen that this invention provides a control system wherebythe drivemotor is automatically brought up to a preselected speed by means of successive secondary.resistance.steps; and is brought to rest by means of successive .secondary'resistance steps. Further, the presetspeedsettingcan .be changed from a remote control stat-ion,-at-.any timeduringenergization .of the main drive motor, including speed up and slow down operations of thelatter.

Although Lhaveshown and described certain specific embodimentsof .my invention, I am fully aware that many modificationstthereof are possible. My invention, therefore, is not to 'be restricted except insofar as is necessitated .bythe prior art and by the spirit of the appended claims.

I claim:

1- In .atswitching .controller, the combination with a rotatable ,operatingfshaft, of .a switch having cam operatingrmeans, adriving member associated with said shaft andsaidcam operating means to normally effect opera- 'tion of.said.switch:in.accordance with rotation of said shaft, .slip-clutchrneans interposed between said driving member and ,saidroperating shaft, and means including electrorespon'sive means energizable to render said driving member non-rotatable to thereby be ineffective to operate said switch regardless of the rotation of said shaft.

12. .In aswitchi-ng controller, the combination with a rotatableoperating shaft, of a switch having cam operatingmeans, a driving mernber for said operating means disposed about "said shaft, a second member disposed about said shaft and non-rotatably secured to said driving member,la'friction 'disc'fixed to said shaft andinterposed between said second and driving members to normally effect rotation of said driving member in accordance withthe rotation of said shaft, and meansineluding an electroresponsive device energizable to afford locking of said second member and said drive member against rotationby. said shaft.

'3.In.a switching controller, the combination with a rotatable operatingshaft, of a switch having cam operatingrneans, a driving memberfor said operating means disposedabout said shaft, .a gear member disposed about saidshaftand nonsrotatably secured to said driving memher, a friction disc fired to said shaft and interposed between said driving and gear members to normally efi'ect rotation of said driving member in accordance with the rotation of said shaft, 21 tl.-ird member having a hub portion formed with gear teeth in engagement with the teeth of said gear member, and an electromagnetically operable locking member for engagement with said third member to afford locking of said driving and gear members against rotation by said shaft.

4. In an electrical controller, the combination with a rotatable operating shaft and a plurality of switches having individual cam operating means, driving members disposed about said shaft and engageable with each of said cam operating means to normally effect predetermined sequential operation of certain of said switches in accordance with rotation of said shaft, a discshaped member disposed about said shaft and nonrotatably secured to one of said driving members, a friction disc fixed to said shaft and interposed between said one of said driving members and said disc-shaped member to normally effect rotation of said one of said driving members, and locking means including an electromagnetically operable device energizable to render said disc-shaped member non-rotatable during the rotation of said shaft.

5. In an electrical switching controller, the combination with a plurality of electric switches operatively associated with a rotatable operating shaft to normally provide for sequential operation of said switches, of means operatively associated with said shaft and including an electromagnetically operable device effective to change the time of operation, in said sequence, of one of said electric switches.

6. In an electrical switching controller, the combination with a plurality of electric switches operatively associated with a rotatable operating shaft to normally provide for sequential operation of said switches, of means operatively associated with said shaft and including an electromagnetically operable device effective to change the time of operation, in said sequence, of one of said electric switches, said means further including clutch means interposed between said shaft and said one of said electric switches.

7. In an electrical switching controller, the combination with a plurality of electric switches operatively associated with a rotatable operating shaft to normally provide for sequential operation of said switches, of means operatively associated with said shaft and including an electromagnetically operable device effective to change the time of operation, in said sequence, of one of said electric switches, said one of said electric switches having cam operating means therefor associated with said operating shaft, and slip-clutch means interposed between said cam operating means and said operating shaft.

8. In an electrical switching controller, the combination with a plurality of electric switches operatively associated with a rotatable operating shaft to normally provide for sequential operation of said switches and a limit switch operatively associated with said shaft to provide for termination of such sequential operation at a predetermined position in the sequence, of means operable to effect change in the above-:.:entioned predetermined position including a pair of reversely effective manually operable electric switches to respectively provide reverse sequential operations of said plurality of electric switches from said predetermined position and to establish a different position of termination of said sequence.

9. In an electrical switching controller, the combination with a plurality of electric switches operatively associated with a rotatable operating shaft to normally provide for sequential operation of said switches and a limit switch operatively associated with said shaft to provide for termination of such sequential operation at a predetermined position in the sequence, of means operable to elfect change in the above-mentioned predetermined position including a pair of reversely effective manually operable electric switches to respectively provide reverse sequential operations of said plurality of electric switches from said predetermined position and to establish a difierent position of termination of said sequence, said means including an electromagnetically operable device energizable in response to operation of either of said pair of manually operable switches to interrupt the effectiveness of said limit switch to terminate sequential operation and deenergizable to restore the effectiveness of said limit switch upon termination of operation the last operated one of said pair of manually operable switches.

10. In an electrical switching controller, the combination with a plurality of electric switches operatively associated with a rotatable operating shaft to normally provide for sequential operation of said switches and a limit switch operatively associated with said shaft to provide for termination of such sequential operation at a predetermined position in the sequence, of means operable to effect change in the above-mentioned predetermined position including a pair of reversely effective manually operable electric switches to respectively provide reverse sequential operations of said plurality of electric switches from said predetermined position and to establish a different position of termination of said sequence, said means including a slip-clutch interposed between said limit switch and said shaft and an electromagnetically operable device energizable in response to operation of either of said pair of manually operable switches to interrupt the effectiveness of said limit switch to terminate sequential operation and deenergizable to restore the effectiveness of said limit switch upon termination of operation of the last operated one said pair of manually operable switches.

References Cited in the file of this patent UNITED STATES PATENTS 2,138,243 Nicolaus Nov. 29, 1938 2,294,573 Potter Sept. 1, 1942 2,476,377 Le Clair July 19, 1949 

